Reversible double ended fuse plug



Aug. 22, 1933. w, LUSH 1,923,156

REVERSIBLE DOUBLE ENDED FUSE PLUG Filed Dec. 18. 1929 V WWW '4 IN ENTOR.

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Patented Aug. 22, 1933 1,923,156 REVERSIBLE DOUBLE ENDED FUSE PLUG William J. Luse, New York, N. Y.

Application December 18, 1929 Serial No. 414,984

This invention is a reversible double ended 17 Claims.

screw fuse plug adapted to be used twice, and

the primary object of the invention is to provide an unusually simple, economical and efficient construction of this character which will embody, among other features, means to indicate when one end of the fuse has been blown, means to indicate amperage for which the particular fuse is to be used, and to so construct the fusev prevent dangerous back that it will effectually plained.

The present invention greatly simplifies manufacturing and assembling of a double ended plug and permits a better plug to be made in a more economical manner than heretofore possible.

In one of its preferred, practical forms, the

plug of the present invention comprises a body portion embodying two complementary parts,

which, in practice may be of identical structure. They may be molded, pressed or otherwise made of fiber, glass, porcelain, or any other suitable insulating material, and each part is so shaped as to constitute one complete end portion of the plug and one semicircular half of the intermediate portion. When two ofthose sections are placed in complementary relation, they are adapted to be secured together by merely screwing on to the opposite endsof the plug the usual metallic screw sleeves. The cooperating sections of the plug may be provided with semicircular channels adapted to collectively register to pro vide an interior circumferential channel adapted to held a partition in place so as to divide the interior of the plug into two distinct chambers in each ofwhic'h the fuse element is positioned.

The fuse elements are associated with the plug in a novel manner as will hereinafter be more fully explained and they are carried from the interior of the plug through the side wall thereof and into a position sponding shell where shell by a drop of solder which is adapted to be positioned Within a recess in the plug in such manner as to form a key between the shell and atone end of the correthey are secured to the the plug and thereby lock the shell against unscrewing. Semicircula cular openings for ven poses.

r openings are provided ting or for tell-tale pur- Another feaure .of the invention consists in carrying the fuse element from the interior of the plug through an opening in the side wall thereof beneath the 'metal sleeve and venting through this opening so as to utilize the sleeve as a sort of mufiier to dissipate the-force of gases generated during blowing of the fuse before they arc discharged into the outer atmosphere. I

Another feature of the invention resides in the provision of a cap adapted'to screwon to that end of the fuse plug which is not'in use as a fuse, said cap serving to cover and conceal said. end of the plug.

Features of the invention, other than those specified, will be apparent from the hereinafter detailed description and claims, when read in conjunction with the accompanying drawing. The accompanying drawing shows one praa tical embodiment of the invention, but the construction therein shownis to beunderstood as illustrative, only, and not as defining the limits of'the invention.

Figure 1 is a perspective section.

Figure 2 is a side elevation of the fuse of this invention showing one section in full lines, the

view of' one fuse opposing section in dotted lines and on metal I so that they may be made in a single mold, all

alike, and any two assembled toform a complete plug. Each section embodies a semicylindrical tubular portion 1 on one end of which is-formed an integral cylindrical portion 2 provided on its outer side with a somewhat smaller substantially semispherical domed end 3. All parts of this section are formed so that they will readily draw fromfa mold and for this reason the inner end 4 of the cylindrical portion 2 is fiat throughout, but is provided with an axial passage 5 through which the fuse element may be passed.

mediate its ends with an enlarged flange'fi maybe semicylindical as shown or may be sen 1- hexagonal. In practice, the cylindrical flange [.The semicylindrical part 1 is provided inter- I may be used on fuse plugs of over 15 amperes, while the same hexagonal flange may be employed to denote fuses of 15 amperes or under,

although other means for indicating amperage may be employed.

The outer or peripheral face of the flange 6 may be knurled or otherwise roughened, so as to better function as a finger piece for screwing in or removing the fuse plug, if the flange is hexagonal, knurling is not necessary.

.Each section 1 is shown as provided intermediate its ends with a semicircular channel 7 to receive a part of a partition 8 having a perforation 22. However, if desired, the partition 8 may be molded in semi-circular halves which are integral with the respective section as shown in Figure 6. In this latter case,'the perforation in said partition can be cast one half in each part so as to register to form the perforation when the parts are brought together.

Semicylindrical passages 9 are cast in the edge of the part 1 and an opensided notch 10 is also preferably molded in the end of the part 1. A pocket or depression 11 is molded in the dome 3 adjacent the shoulder 12 on the base of this dome.

The fuse'element, designated 14, is adapted to be passed through the passage 5 in the cylin drical part and is secured therein by a split rivet 15 as shown best in Figs. 1 to 3. The of the rivet bears against a short projecting portion of the fuse element at the outer end of the dome 3 while the inner end of the rivet is bent outwardly to clamp the parts firmly in 7 place. The fuse element is looped, as shown and extends over, the edge of each cylindrical part 4, as shown in Figs. 1 and 3. The free edge left extending while two sections of the character shown in Fig. 1 are placed in come plementary relations as indicated in Fig. 2. If

the separate partition 8 is to be used, it is slipped into place before the two sections are assembled. After assembly, the metal sleeves 16 are passed over the opposite ends of the sections and ridges or. projections 17 formed upon said sections act asthreads on which the sleeves may be screwed cov until the flanges 18 at the outer ends of the sleeves abut the shoulder 12 as shown in Figure 3. If a separate circular partition is fittedinto the semi-circular channels, as shown, this partition acts as a key to lock the sections against relative longitudinal shifting.

It will be noted that the fuse elements 14 pass from the interior of the fuse through openings 10 which are positioned beneath the sleeves 16. These fuse elements may be carried along the plug to either the inner or outer ends of thesleeves as maybe desired. If carried to the outer end of the corresponding sleeve, the fuse element is secured to the sleeve by means of a drop of solder indicated atj23 so formed as to Y extend into the pocket 11 and form a key to lock the sleeve against rotation. A similar pocketlla may also be formed in each plug section adjacent the innerend of each sleeve, and a drop of solder 23a introduce-d thereinto and attached to thesleeve toform anadditional key at this point. If the fuse element is carried to the inner end of the sleeve itmay be secured to the sleeve by this drop of solder 2360. When the s1ejevesfare in place as stated, they will clamp the sections of the plug firmly together and will preclude'movement of such sections'in all directions.v Furthermore, the'solder keys 23 or 23a will firmly lock the sleeves against rotaniuffling elfect.

tion on the sections and make the assembly a.

ings which may be used for venting purposes.

Into one or more of these openings on either side of I the partition may be introduced mica disks 21 to act as tell-tales for the purpose of showing when the fuse has blown, for when the fuse blows, it will cloud or smoke a piece of mica to clearly show that the fuse has blown.

Venting of the interior of the plug is had through suchof these opening as are not sealed by the mica as well as through the openings 1( through which the fuse elements] preferably extend. These openings 10 are covered by the sleeve so that as the gases blow through the openings,-

they are discharged into the interior 7 of the sleeves in which their force is spent with a andthe plug sections which they embrace will operate as a muii'ling space and there is sufiicient leakage about the endsof the sleeves to permit escape of the gases. One or more pockets 110. may beprovided to permit the escape of these gases. i

In practice, I preferably color one end of the plug and leave the otherend of the plug in its natural state. In use, the colored end is used first, so that if a person sees the colored end showing outside of the fuse plug socket, he will The space between the sleeves know that the plug cannot be turned around as I the outer end has already blown. v

In Figure 5,I have shown a cap of insulating material provided on its interior with threads and of asize to permit these threads to screw over either end of the plug." The purpose of this cap is to cover and conceal the end of the,

plug which is not introduced into the'socketfof the fuse box, inorder that thedesign of the end of the fuse plug cap will harmonize with the standard single plugs in appearance, especially where uniformity and neatness are desired, in glass cabinets, etc. In any event the use of the cap may be eliminated-and in the event the cap cover is used, a special color or other identi fication may indicate amperage.

The plug of this invention is of unusually simple construction. It may be economically manufacturedand is thoroughly eflicient in its operations. It has a relatively large explosion chamber at either side of the partition and the perforation of the partitionlallows explosive gases within either chamberof the plug, toes-.

cape into the other chamber without the risl; of blowing the fuse in the later chamber. The

arrangement of the parts is such that, flash backs, such as commonly occur in the wellknown single fuses now inuse' which embody mica windows, will not occur with the fuse of the present invention because there is adequateprovision for the escape 'OfGXPlQSlVE gases coupledwith solid fuse plug end." Furthermore, the sleeves lock the sections of the plug together and are thus locked-to the sections in a manner to absolutely preclude the unscrewing of" the tion with the fuse element.

was 5 6 "sections and by the solder keys 23 and 230.

which I have described. Withthis plug, the

attempt to unscrew a'plugfrom a socket cannot possibly result in the loosening of the Sleeve from the plug asso commonly occurs in fuse plugs as now constructed. On the contrary, the arrangement is such that the sleeves cannot possibly become disengaged fromthe fuse sections. J

I call attention tothe marked simplicity with which the fuse elements are secured at the end of the plug sections. An ordinary split rivet not only serves to accomplish this result, but the head'of the rivet functions as the end contact of the plug and has a good electrical connec- This fuse element may in practice be of any suitable character such as wire or strip fuse materiaL'and it may be weakened as by flattening it or perforating it as shownat 24 in Fig. 1, so that when it blows it will be ruptured at this point.

The amperage may be identified, in addition to the manner alreadydescribed by having the center peripheral flange 6 colored on both sides to denote under or over a certain amperage. of

the fuse plug,'or the ends of the plug may be colored to denote the individual amperage of each plug.

When using the ends'of fuse plug to denote amperage, I employ in lieu of the one colored end which indicates when this end has been used on the fuse plug, another means of coloring only one side of the peripheral flange 6 which answers the same purpose, as the one colored end of fuse plug when used or blown.

The advantages are that the operator becomes better acquainted with the fuse plug problem, in that he may instantly determine the proper ampere fuse to use by noting the colors on plug ends. He can also readily determine when one end.of the fuse plug has already been used. This'indicating means on the fuse plugs is very important, as without this indication, one is placed at a great disadvantage,

in many ways. Delay, Worry, difficulty and negligence is thus eliminated to a great extent by the said means of not only indicating the proper fuse plug to use, but also denoting When one end of the fuse plug has been used.

It will be apparent from the foregoing detailed description that the fuse plug of this invention embodies several novel features some of which in practice may be employed without necessarily employing all of them. Furthermore,

structural details may be modified without departing from this invention. For these reasons,

the invention is not to be understood as restrict-' a cylindrical plug body, one end of each of said semicylindrical sections being provided with an integral circular end piece adapted to serve as a closure for the opposite ends .of the cylindrical body when said sections are assembled, said sections being provided interiorly with circumferential channels adapted to register when the sections are assembled and a partition peripherally engaging said channels and held in place there'- by, said partition serving to lock the sections against relative longitudinal movement.

2. A double ended fuse plug comprising a pair of complementary semicylindrical sections adapted'to be placed in edge abutting relation to form a cylindrical plug body, one end of each s: said semicylindrical sections being provided with an integral circular end piece adapted to serve as a closure for the opposite ends of the cylindrical body when said sections are assembled, andthreaded metallic sleeves embracing the opposite end portions of the cylindrical body to secure said sections together, said sleeves being exteriorly threaded to screw into a fuse socket.

3. A double ended fuse plug comprising a pair of complementary semicylindrical sections adapted to be placed in edge abutting relation to form a cylindrical plug body, one end of each of said semicylindrical sections being provided with an integral circular end piece adapted to serve as a closure for the opposite ends of the cylindrical body when said sections are assembled, and threaded metallic sleeves embracing the opposite end portions of the cylindrical body to secure said sections together, said sections being provided adjacent one end of each sleeve with a depression, and solder secured to the its sleeve and extending into the depression to selie tions together, said sections being provided adjacent one end of each sleeve with a depression,

and solder. secured to the sleeve and extending into the depression to secure the sleeves against removal from the cylindrical body, a center contact positioned at the outer end of the circular 7 part of each section, and a fuse element eXtend- 1 ing from each contact through said circular part into the interior of the cylindrical body and thence to said solder to be secured thereby to the corresponding metallic sleeve.

5. A double ended fuse plug embodying a pair of identical fuse sections of insulating material positioned in complementary relation and forming a complete fuse body closed at both ends,

"and threaded sleeves embracing the opposite end portions of both sections to maintain them in assembled relation, said sleeves being adapted to screw into a fuse socket.

- 6. A double ended fuse plug embodying a pair ice of identical fuse sections of insulating material positioned in complementary relation and forming a complete fuse body closed at both ends, and threaded sleeves embracing the opposite end portions of both sections to maintain them in assembled relation, contacts on the opposite ends of the body, and fuse elements. electrically connecting the contacts to the sleeves.

7. A double ended fuse plug embodying a pair of identical fuse sections of insulating material ing a complete fuse body closed at both ends,

positioned in complementary relation and form-3 3., 0k

said sections being provided interiorly with circumferential channels adapted to register when. the sections are assembled, and a partition peripherally engaging said channels and held in place thereby. V

8. A double ended fuse plug embodying a pair of identical fuse sections of insulating material. positioned in complementary relation and form ing a complete fuse body closed at both ends,

said sections being provided interiorly with circumferential channels adapted to register when the sections are assembled, and a partition pe-- ripherally engaging said channels and held in place thereby, said partition serving to lock the: sections against relative longitudinal movement, and threaded metal sleeves embracing the op-- posite ends of the sections to hold them in. assembled relation.

9. A double ended fuse plug embodying a pair of identical fuse sections of insulating material positioned in complementary relation and. forming a complete fuse body closed at bothv ends, each of said sections having an exteriorprojection constituting a thread, a metal sleevescrewed on tosaid threads to secure the sec-- tions together, a contact on each end of thei'use body, and a fusible clel lent electrically connecting each contact to the corresponding sleeve.

10. A double ended fuse plug embodying a. pair of identical fuse sectionsv of insulating ma terial positioned in complementary relation and forming a complete fuse body closed at both ends, each of said sections having a peripheral. channel and anexterior projection constituting a thread, a metal .sleeve screwed on to said threads to secure the sections together, a contact on each end of the fuse body, and a'fusible element electrically connecting each contact to the corresponding sleeve, the inner ends of thesleeves being flanged into the peripheral chan nels of the sections to removably secure the sleeves in position thereon.

11. A double ended fuse plug embodying a pair of identical fuse sections of insulating material positioned in complementary relation and forming a complete fuse body closed at both ends, said sections being provided along the joint between them with openings formed collectively in both sections.

12. A double ended fuse plug embodying a pair of identical fuse sections of insulating material positioned in complementary relation and forming a complete fuse body closed at both ends, said sections being provided along the joint between them with an opening through the wall of the body.

lpair of complementary semicylindrical sections adapted to be placed in edge abutting relation to form acylindrical plug body, one end of each LOf said semicylindrical sections being provided with an integral circular end piece adapted to serve as a closure for the opposite ends of the cylindrical body when said sections are assem- '.bled, threaded metallic sleeves embracing the opposite end portions of the cylindrical body to secure said sections together, said sections being provided adjacent one end of each sleeve with a depression, and the wall of the plug body being perforated beneath the sleeves, to permit gases to pass from within the body into the space between the body and the sleeves and (DILlt through said depressions.

14. A double ended fuse plug provided intermediate its ends with an enlarged peripheral flange colored to indicate amperage.

15. A reversible fuse plug comprising a pair of \identical insulating sections, each section having a tubular semicylindricalwall with an integral semicircular internal partition located medially of the length thereof and having a semicircular hole in the center of the chord edge of said partition, a cylindrical end portion integral with one end of each tubular wall to close the opposite ends of the plug, each of said sections having an opening when said sections are placed in co-relation for the passage of a fuse strip and to serve as a vent, a thread formed on the exterior of each section, metal collars permanently screwed onto said threads to securely. clamp the sections together against displacement in all directions, contact points centrally located at the opposite ends of the cylindrical portions, fuse strips attached to said contacts and extending through the interior of the plug to' and electrically connected with the metal collars at the corresponding ends of the plug. I

16. A double ended fuse plug embodying a pair of L-shaped fuse sections of insulating material positioned in complementary relation and forming a complete fuse 1 body .closed at both ends, each of said sections being provided in 

